Jothybasu Selvaraj1, Joos Lebesque1, Andrew Hope2, Matthias Guckenberger3, Maria Werner-Wasik4, Heike Peulen1, Meredith Giuliani2, Frederick Mantel5, José Belderbos1, Inga Grills6, Jan-Jakob Sonke7. 1. Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. 2. Department of Radiation Oncology, University of Toronto and Princess Margaret Cancer Center, Canada. 3. Department of Radiation Oncology, University of Wuerzburg, Germany; Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Switzerland. 4. Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, USA. 5. Department of Radiation Oncology, University of Wuerzburg, Germany. 6. Department of Radiation Oncology Beaumont Hospital, Royal Oak, USA. 7. Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. Electronic address: j.sonke@nki.nl.
Abstract
PURPOSE: To investigate if a local dose-effect (LDE) relationship for perfusion loss improves the NTCP model fit for SBRT induced radiation pneumonitis (RP) compared to conventional LDEs. METHODS AND MATERIALS: Multi-institutional data of 1015 patients treated with SBRT were analyzed. Dose distributions were converted to NTD with α/β = 3 Gy. The Lyman-Kutcher-Burman NTCP model was fitted to the incidence grade ≥2 RP by maximum likelihood estimation with mean lung dose (MLD), equivalent uniform doses (EUD) using three LDE functions (power-law (EUDpower), logistic with 2 free parameters (EUDlog-free) and logistic with fixed parameters describing local perfusion loss (EUDPerfusion)) and volume above a threshold dose (Vx). Models were compared with the Akaike weights (Aw) derived from the Akaike information criteria (AIC). RESULTS: The median time to grade ≥2 RP was 4.2 months and plateaued after 17 months at 5.4%. A strong dose-effect relationship for RP incidence was observed. The EUDPerfusion based NTCP model had the lowest AIC. The Aw were 0.53, 0.19, 0.11, 0.11, 0.05 for the EUDPerfusion, Vx, MLD, EUDlog-free and EUDpower LDEs respectively. CONCLUSION: A LDE for perfusion loss provided modest improvement in NTCP model fit for SBRT induced radiation pneumonitis.
PURPOSE: To investigate if a local dose-effect (LDE) relationship for perfusion loss improves the NTCP model fit for SBRT induced radiation pneumonitis (RP) compared to conventional LDEs. METHODS AND MATERIALS: Multi-institutional data of 1015 patients treated with SBRT were analyzed. Dose distributions were converted to NTD with α/β = 3 Gy. The Lyman-Kutcher-Burman NTCP model was fitted to the incidence grade ≥2 RP by maximum likelihood estimation with mean lung dose (MLD), equivalent uniform doses (EUD) using three LDE functions (power-law (EUDpower), logistic with 2 free parameters (EUDlog-free) and logistic with fixed parameters describing local perfusion loss (EUDPerfusion)) and volume above a threshold dose (Vx). Models were compared with the Akaike weights (Aw) derived from the Akaike information criteria (AIC). RESULTS: The median time to grade ≥2 RP was 4.2 months and plateaued after 17 months at 5.4%. A strong dose-effect relationship for RP incidence was observed. The EUDPerfusion based NTCP model had the lowest AIC. The Aw were 0.53, 0.19, 0.11, 0.11, 0.05 for the EUDPerfusion, Vx, MLD, EUDlog-free and EUDpower LDEs respectively. CONCLUSION: A LDE for perfusion loss provided modest improvement in NTCP model fit for SBRT induced radiation pneumonitis.
Authors: Vitali Moiseenko; Jimm Grimm; Ellen Yorke; Andrew Jackson; Anthony Yip; Minh-Phuong Huynh-Le; Anand Mahadevan; Kenneth Forster; Michael T Milano; Jona A Hattangadi-Gluth Journal: Cureus Date: 2020-10-05